331 stroked 302 fuel pressure question

[stroked331stang]

I have a 331 stroked 302. It has a wolverine cam, edelbrock performer rpm upper and lower intake manifold, 70mm accufab t-body, ported and polished gt40 heads, 30lb injectors and maf to match. The car runs rich you can smell it from standing in front of the car with the hood open, it actually makes me cough. At 1/4 throttle (while your driving) you can feel the rpm kinda not steady, it kinda jerks the car back and forth. I'm pretty sure I don't need 30 lb injectors and wondering how much i should lower my fuel pressure.

The guy i bought the stang from said the car put 340hp to the wheels on a dyno. When i bought the car the fuel pressure was set at 50 with the hose capped. I lowered it to stock 39-40psi and it is much better but i still feel the jerkiness a little bit. The car definitely does not lack power, its a torque beast. Just wondering if lowering it too much will hurt the power.

 

[Kdubslugga]

Yeah 50 psi is way to high. 39-40 psi is where you should be. Your not hurting your performance by lowering it, your probably helping it, there is no way to tell where your FP should be unless your on the dyno. Buy id leave it at 40

 

[stroked331stang]

I don't know what the last owner was thinking, 30 lb injectors and 50psi fuel pressure?...That will probably support 600hp when I''m just around 380-400 at the crank. Last night i lowered the pressure down to 35 psi with hose capped, at idle I'm getting 29psi. All i can say is i definitely feel a boost in power tuned this way it was like a night and day difference...no pinging or anything either. I drove all day today and seems good. One of these days I'll have to put it on a dyno and see how the air/fuel ratio is and maybe i can get even more power out of it with more fine tuning of the fuel pressure.

 

[Rick 91GT]

I don't know what the last owner was thinking, 30 lb injectors and 50psi fuel pressure?...That will probably support 600hp when I''m just around 380-400 at the crank. Last night i lowered the pressure down to 35 psi with hose capped, at idle I'm getting 29psi. All i can say is i definitely feel a boost in power tuned this way it was like a night and day difference...no pinging or anything either. I drove all day today and seems good. One of these days I'll have to put it on a dyno and see how the air/fuel ratio is and maybe i can get even more power out of it with more fine tuning of the fuel pressure.

The only time your actually getting the extra fuel from the regulator is up top at WOT, otherwise the EEC will trim the amount of fuel you are actually getting. Does the car have a chip? The only reason I ask is at times, some tuners will add the fuel through the regulator instead of the chip, not exactly the way I like to do it but it works...

At idle the 30# inj will dump a little too much fuel, it can be trimmed out with a good tune and that will help with the overly rich condition down low. I think youll be fine with 35-38psi vac off. A few runs on a dyno will do some good

 

[stroked331stang]

I don't know if it has a chip, I'm guessing the computer is stock. I'll have to make an appointment with a dyno shop this summer.